I'm looking for...

...a copy of Chaosium's "Worlds of Wonder" boxed set, from 1982.

You can read James Maliszewski sing its praises here.

I have three of the four booklets already, but it's the additional material that I'd really like to get my hands on.

(Although if a complete set were to turn up, I'd be very interested.)

Thanks for any help anybody can provide.